Nokia Virtualized Service Router - Route Reflector

Nokia Virtualized Service Router - Route Reflector Creating a new benchmark for performance and scalability

Application Note

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Application Note Nokia Virtualized Service Router – Route Reflector

Abstract Network function virtualization (NFV) has attracted much recent attention. NFV transforms specific network function that run on specialized, dedicated hardware platforms into software function implemented on general-purpose computing platforms. NFV offers added flexibility and faster timetomarket, enabling new ways to deliver services. Nokia has over a decade of industry leadership and innovation in IP routing platforms, Service Router OS (SR OS) software, and network/service management. The company is embracing the move to NFV and is committed to delivering virtualized solutions that help network operators reach their NFV goals. Leveraging the SR OS and designed for x86 server environments, the Nokia Virtualized Service Router (VSR) is the industry’s first virtualized IP/MPLS router. BGP route reflection is an ideal function for virtualization. The VSR - Route Reflector (VSR-RR) leverages key innovations and has set a new benchmark for RR performance and scale compared to alternate virtualized RR implementations.

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Application Note Nokia Virtualized Service Router – Route Reflector

Contents Introduction

4

BGP RRs

4

Virtual BGP RRs

5

Nokia VSR: Architected for NFV

5

Parallel SMP

6

64-bit OS support

7

VSR-RR: Flexible deployment options

7

VSR-RR: Raising the bar for performance and scale

8

VSR-RR reference information

10

Standards and protocols

10

Host, hypervisor and licensing information

10

Conclusion

11

Acronyms

11

References

12

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Application Note Nokia Virtualized Service Router – Route Reflector

Introduction Network function virtualization (NFV), defined by the European Telecommunications Standards Institute (ETSI)1, aims to transform the way that network operators design networks by evolving network equipment function onto industry-standard, high-volume servers. The application of NFV introduces many benefits, including rapid scaling of services, faster time-to-market, and in some cases reduced costs from economies of scale by using standard IT-server virtualization technology. Building on over a decade of investment and industry recognition with its Service Router (SR) portfolio, Nokia has introduced the industry’s first virtualized IP/Multiprotocol Label Switching (MPLS) router: the Nokia Virtualized Service Router (VSR). The VSR is highly flexible, enabling rapid service innovation, elastic scalability, and lower operating costs with a homogenized physical infrastructure and NFV management and orchestration. Based on the Nokia Service Router Operating System (SR OS) and architected for x86 server environments, the VSR delivers the IP service richness, reliability and resiliency required to gain a competitive edge in delivering IP networking services. The VSR provides a suite of virtualized function and services:2 This application note focuses on the VSR Route Reflector (VSR-RR). The VSR-RR is functionally and operationally equivalent to a Nokia 7750 Service Router hardware-based BGP RR, with the added benefits of delivering higher flexibility, scale and performance. For information about other virtualized function, see the most recent Nokia VSR data sheet.

BGP RRs In a standard BGP configuration, a BGP route learned from one Internal BGP (iBGP) peer is not readvertised to another iBGP peer. This rule exists because of the assumption of a full iBGP mesh within an autonomous system. A full iBGP mesh imposes scaling challenges when many BGP peers exchange large amounts of routing information. BGP route reflection eliminates the need for a full iBGP mesh by using one or more designated BGP RRs to re-advertise routes from one iBGP peer to another iBGP peer. A RR and its iBGP peers (clients) form a cluster. To prevent single points of failure, a cluster may implement multiple RRs for redundancy. In addition, route reflection duties can be distributed over different BGP RRs based on address families. In today’s networks, the RR function is predominantly run on an IP router that is dedicated for route reflection or that performs the RR function in addition to other IP routing and services function. The RR function is primarily run on the router control card, and the performance and scale of route reflection is mostly determined by the control card’s hardware specifications (CPU type, speed and memory).

1 Margaret Chiosi et al., Network Function Virtualisation: An Introduction, Benefits, Enablers, Challenges & Call for Action. SDN and OpenFlow World Congress, Darmstadt-Germany, October 2012. http://portal.etsi.org/NFV/NFV_White_Paper.pdf 2 Please refer to the Virtualized Route Reflector (VSR) datasheet. Link available in the References section of this document

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Application Note Nokia Virtualized Service Router – Route Reflector

High-end routing platforms with next-generation control cards are often required to meet RR requirements in today’s networks. A router used solely for the RR function is underutilized in the data plane because the RR function require minimal data-plane resources. Conversely, a router that shares the RR function with other IP routing functions may not have sufficient resources (CPU and memory) to support scalable route reflection. A router-based RR model is restricted in its ability to flexibly scale up: improve performance and scale with evolving network requirements. A new router platform may be required to support additional RR capabilities. In addition, some network operators may want to deploy separate RRs for specific applications, such as Internet routing, Layer 3 (L3) virtual private network (VPN), and Layer 2 VPN. This inflexibility increases costs related to deploying and scaling RRs.

Virtual BGP RRs BGP route reflection is mainly a control-plane function with minimal traffic in the data plane, making it ideal for virtualization. The RR operation is memory and compute-intensive and is well suited to run on x86-based server platforms. A virtualized RR (vRR) removes reliance on dedicated hardware, which lacks sufficient performance and scale in the control plane and/or which may be underutilized in the forwarding path. A vRR offers more flexible deployment options and upgrades for improved scale and performance. Scale and performance levels can be adjusted up or down as needed by flexibly allocating server (host) resources to the vRR. A vRR can be deployed as a single RR for all applications or with dedicated RRs for specific address families and applications, such as Internet routing, L3 VPNs and L2 VPNs. This flexibility enables innovative deployment and operational models: for example, a vRR instance could be automatically restarted on a new server in case of failure of the vRR that was previously executing the function.

Nokia VSR: Architected for NFV Moving to an NFV deployment model requires that virtualized network function take full advantage of the underlying IT-server virtualization technologies (with extensive multicore support and significantly larger memory capacity offered by host machines). The Nokia Virtualized Service Router (VSR) is based on a real-time, modular, highly fault-tolerant design. It features several industry-leading architectural innovations for implementing virtualized network function. Robust and highly scalable, the VSR is purpose-built for x86-based hosts and leverages the widely deployed and field-proven SR OS. The VSR has been designed for reliability and High Availability (HA), and it features several innovations that take advantage of the unique attributes provided by x86based hosts.

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Application Note Nokia Virtualized Service Router – Route Reflector

The VSR and its network applications are managed by the Nokia 5620 Service Aware Manager (SAM), which also manages traditional Nokia 7750 SR network applications. Nokia offers a comprehensive NFV and software defined networking (SDN) portfolio that includes: • CloudBand™ Management System • Nuage Networks™ Virtualized Services Platform With a broad ecosystem of partners, Nokia provides network operators with a complete, fully integrated NFV infrastructure. Table 1 lists key VSR features and benefits. Table 1. VSR features and benefits FEATURE/BENEFIT

DESCRIPTION

Flexible deployment models

Deployment options: • Integrated system (single virtual machine [VM] supports control-plane and data-plane function) • Distributed system (control-plane and data-plane function distributed across multiple VMs) The VSR-RR is implemented using the integrated system model. VSR-PE and VSR-AA can be implemented using the integrated or distributed system model.

Designed for scale

Processing power scales up as [virtual] CPUs and memory are added to a specific VM and scales out as VMs are added in a distributed deployment model.

Real-time OS

Fine-grained scheduling prioritizes high priority processes for faster convergence and control-plane responsiveness while maintaining fairness.

Modular process architecture

Process separation protects individual processes.

Fault-tolerant design

Highly reliable Non-Stop Services for mission-critical applications, with HA and in-service software upgrades for the distributed system model

Best practises in large-scale system design

Optimized custom OS, rigorous design practises, strict APIs, and memory protection that scales across diverse architectures

Strict separation of control-plane and data-plane function

Supported for the distributed deployment model

In addition to the capabilities listed in Table 1, two innovations provide significant benefits for virtualized network function: parallel Symmetric Multi Processing (SMP) and 64-bit OS support.

Parallel SMP Multicore CPUs provide highly scalable processing power that impr oves routing convergence times for high-performance routing applications and services. To further enhance the power of multicore processing, Nokia has created a unique approach to software OS design. The VSR supports parallel SMP, a multi-threaded software approach that enables the concurrent scheduling and execution of different processes on different processor cores. With SMP — supported in the SR OS since 2009 — the VSR unleashes the power and performance of multicore processing to deliver unmatched performance. SMP maximizes performance by taking full advantage of the multicore capabilities of Intel® x86-based hosts (servers), as shown in Figure 1. Running VSR processes in parallel across multiple CPU cores 6

Application Note Nokia Virtualized Service Router – Route Reflector

provides impressive performance benefits. In contrast, a solution that does not support multiprocessing runs on a single core, significantly impacting performance and providing no scale-up capability. In a singleprocessor implementation, the underlying OS cannot take advantage of the additional CPU cores. Figure 1. Maximizing performance with VSR SMP

VSR Process

VSR Process

VSR Process

VSR Process

Virtualized Process

Core 0

Core 1

Core 2

Core 3

Core 0

Core 1

Core 2

Core 3

VSR Process

VSR Process

VSR Process

VSR Process

Core 4

Core 5

Core 6

Core 7

Core 4

Core 5

Core 6

Core 7

SMP with Nokia VSR

Single processor implementation with “Vendor X”

64-bit OS support With a 64-bit OS, processes can access a much larger memory address space compared to a 32-bit OS. This capability has been proven for 7750 SR deployments. The latest 7750 SR control processing cards (SF/CPM5 with 16 GB of RAM) support 8 million unique IPv4 routing information base (RIB) routes with a 32-bit OS image and 46 million RIB routes — an almost six-fold increase — with a 64-bit OS image. x86based servers can support hundreds of GB of memory space. A 64-bit OS can fully exploit this additional space with the potential for enabling very high scaling for specific virtualized function.

VSR-RR: Flexible deployment options The VSR-RR is deployed as an integrated single VM system that includes the control-plane and dataplane function. Each VM is assigned virtual resources — CPU, memory and network interface cards — from the host’s available resource pool. For maximum scaling flexibility, VM resources can be scaled up or down as required to meet evolving performance and scaling needs. The VSR-RR is modeled as a router, with a control card and a line card that supports five Gigabit Ethernet ports and one or more CompactFlash® devices. The VSR-RR supports the same routing features as a Nokia 7750 SR-based (relevant to a control-plane RR). Virtual route reflection can be deployed with a single VSR-RR that supports all applications or, as shown in Figure 2, with separate VSR-RRs for separate address families and applications — Internet, L3 VPN, L2 VPN — with the option to deploy multiple VSR-RRs for redundancy. VSR-RRs can be independently scaled up or down to meet specific application requirements (e.g., L3 VPN VSR-RR may be configured to support more VM resources than the Internet access or L2 VPN VSR-RR).

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Application Note Nokia Virtualized Service Router – Route Reflector

Figure 2. Dedicated hardware and virtual RRs Virtual Route Reflectors

Dedicated Route Reflectors

Internet

RR

Internet

L3 VPN

L2 VPN

Internet

L3 VPN

L2 VPN

VSR RR

VSR RR

VSR RR

VSR RR

VSR RR

VSR RR

VM

VM

VM

VM

VM

VM

RR Virtualization

L3 VPN

L2 VPN

RR

RR

RR

RR

Hypervisor

Hypervisor

Host

Host

The VSR-RR is managed under the Nokia 5620 SAM and NFV orchestration systems, which enable the dynamic, rapid and flexible introduction of VSR-RR function.

VSR-RR: Raising the bar for performance and scale The VSR-RR leverages parallel SMP and a 64-bit OS support — to set a new industry benchmark for RR performance and scale: • Increasing VM CPU resources increases performance for route learning and RR. • Increasing VM memory resources increases the scale and number of BGP peers and routing entries. RR performance was tested with the VSR-RR and was compared with an alternate commercially available vRR solution (“Vendor X”) that is not optimized (does not support SMP) for x86-based deployments. Test methodology The vRR test setup matched real network-deployment scenarios, including route learning and route reflection (515,000 IPv4 prefixes) for the full IPv4 routing table for increasing number of BGP peers (100 to 1000 peers). The test measured convergence time: the time taken by the vRR to learn and reflect all routes for an increasing number of BGP peers. Test environment Test equipment from a leading test equipment vendor emulated the BGP peers, providing the Internet prefixes and the emulated BGP RR clients. Equipment/function specifications for the vRR tests are listed in Table 2.

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Application Note Nokia Virtualized Service Router – Route Reflector

Table 2. Host and hypervisor specifications EQUIPMENT/FUNCTION

DESCRIPTION

Host

• Intel Xeon® E5 v2 host platform with a dual CPU motherboard (single CPU used: Intel Xeon E5-2687W v2, 3.4 GHz with 8 cores/16 threads) • Support for Intel Hyper-Threading Technology, with two processing threads per physical core 3 • Host OS: Linux®

Hypervisor

Linux Kernel-based VM (KVM)

VM

Each VM was configured to support: • 8 cores (16 virtual CPUs [vCPUs]/16 threads) • 24 GB RAM

Figure 3. Test results: Nokia VSR-RR vs. alternative vendor’s vRR implementation

Test results The performance of the two vRR implementations is shown in Figure 3.The test results illustrate the significant advantage of the x86 optimized design of the Nokia VSR-RR implementation over an alternative vendor’s vRR implementation.

Vendor X

1534

1000

Number of RR clients

Nokia

180

Nokia VSR-RR

720

500

88

8x

346

250

41

faster

172

100

23 0

500

1000

1500

2000

Convergence time (seconds) -

3 Highly threaded applications can complete more work in parallel, completing processes sooner.

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Application Note Nokia Virtualized Service Router – Route Reflector

For the test setup with 100 RR peers, the VSR-RR converged in just 23s while the alternate solution required 172s to learn and reflect all routes. The VSR-RR performance advantage was maintained when the number of RR clients (BGP peers) increased to 250, 500 and 1000. In each scenario, the VSR-RR performed approximately eight times faster than the alternate implementation. This significant performance advantage can be attributed to SMP support on the VSR-RR. SMP dynamically allocates cores (vCPUs) on demand and runs RR processes in parallel. In Figure 4, a command-line interface (CLI) screen shows how the VSR-RR took advantage of the multicore capabilities of the Intel x86 host. The alternate vRR solution, which was not architected for SMP, used a single core and was therefore unable to match the performance of the VSR-RR. Figure 4. Host CPU utilization: Nokia VSR-RR and Vendor X vRR 4

Nokia VSR-RR vCPU utilization

Vendor X vRR vCPU utilization

VSR-RR reference information Standards and protocols For information about VSR-RR routing/policy standards and protocol support, see the “Standards and protocol support” sections of the Nokia 7750 SR product guides.

Host, hypervisor and licensing information Please refer to the latest Virtualized Service Router (VSR) datasheet. Link is available in the References section of this document. 4 The CLI screen shows host utilization. Cores (vCPUs) that show minimal loading are allocated to Linux host OS processes.

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Application Note Nokia Virtualized Service Router – Route Reflector

8 Conclusion Nokia is embracing virtualization for IP/MPLS service routing. To help network operators realize this vision, the company has introduced the Nokia Virtualized Service Router (VSR): the industry’s first fullservice virtualized IP/MPLS router.. For virtualized IP routing function to deliver true flexibility, scale and performance, the virtualized function implementation must take full advantage of underlying IT-server virtualization technologies. The VSR-RR supports innovations such as parallel SMP and a 64-bit OS. These attributes help deliver superior performance and scale compared to alternate vRR solutions. Nokia leverages over a decade of industry leadership and innovations in IP routing platforms, SR OS software, and network/service management to enable best-of-breed virtualized network function and services. For more information about the Nokia VSR, visit: www.alcatel-lucent.com/products/virtualized-service-router

9 Acronyms 5620 SAM

Nokia 5620 Service Aware Manager

7750 SR

Nokia 7750 Service Router

AA



Application Assurance

API



application programming interface

BGP



Border Gateway Protocol

CLI



command-line interface

CPU



central processing unit

ETSI



European Telecommunications Standards Institute

HA



High Availability

iBGP



internal BGP

IT



information technology

KVM



Kernel-based VM

L2, L3

Layer 2, Layer 3

LAN



local area network

MPLS



Multiprotocol Label Switching

NFV



network function virtualization

OS



Operating System

PE



provider edge

RAM



random access memory

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Application Note Nokia Virtualized Service Router – Route Reflector

RIB



routing information base

RR



route reflector

SDN



software defined networking

SMP



Symmetric Multi Processing

SR



Service Router

SR OS

Nokia Service Router Operating System

vCPU



virtual CPU

VM



virtual machine

VPN



virtual private network

vRR



virtualized RR

VSR



Nokia Virtualized Service Router

VSR-RR

VSR Route Reflector

10 References 1. Nokia Virtualized Service Router, Release 13. Nokia data sheet. March 2015. http://resources.alcatel-lucent.com/?cid=182483 2. Nokia Virtualized Service Router product page www.alcatel-lucent.com/products/virtualized-service-router 3. Chiosi, Margaret, et al. Network Function Virtualisation: An Introduction, Benefits, Enablers, Challenges & Call for Action. SDN and OpenFlow World Congress, Darmstadt-Germany. October 2012. http://portal.etsi.org/NFV/NFV_White_Paper.pdf

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Application Note Nokia Virtualized Service Router – Route Reflector

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